Lancet and method of forming



Oct 1962 J. J. GRIFFITTS E'II'AL 3,060,937

LANCET AND METHOD OF FORMING Filed Sept. 9, 1960 r r of 0 0 .0

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3,060,937 LANCET AND METHOD OF FORMING James J. Griflitts, Miami Shores, and James C. Hobbs II, Miami, Fla, assignors to Dade Reagents Inc., Miami, Fla., a corporation of Florida Filed Sept. 9, 1960, Ser. No. 54,965 7 Claims. (Cl. 128314) This invention relates to a lancet and method of forming the same. The invention is particularly useful as a single use blood-letting instrument for the collection of small amounts of blood for test purposes.

An object of the invention is to provide a lancet having directional resistance for increasing the action of the cutting edge, whereby the maximum number of blood vessels may be cut with a minimum surface lineal cut. Another object is to provide, in combination with a lancet having a cutting edge, means for promoting free bleeding while at the same time promoting quick healing of the cut. A still further object is to provide a lancet having a cutting blade which allows an instrument in a single plane to progress into a three-dimensional .cut, the blade having a section modulus that increases approximately in proportion to the depth of penetration and which produces a gaping wound in proportion to penetration depth. Yet another object is to provide a lancet having a maximum finger area for grasping the lancet while stabilizing the fingers for a desired angle of thrust.

A further object is to provide a lancet having a ribsupported point and a curved or tapering stop area between the point and the main body of the lancet for the elimination of stress which, in turn, reduces the possibility of a fracture occurring between the cutting portion of the lancet and handle in non-ductile material. A still further object is to provide a lancet having a flared handle portion providing for maximal finger frictional contact and -a maximal exposed area, while tending to con- .ceal the point of the lancet. Still another object is to provide a lancet having a plurality of flutes or ribs extending longitudinally of the lancet body, increasing the grip area thereof and providing additional purchase for the fingers, the flutes tapering to a fixed point both in the angle and taper to give maximum section modulus possible at the junction of the handle and knife. Yet a further object is to provide a flute-reinforced lancet and having the advantages set out hereinafter. Other specific objects and advantages will appear as the specification proceeds.

The invention is shown, in an illustrative embodiment, by the accompanying drawing, in which:

FIG. 1 is a perspective view of a lancet embodying our invention; FIG. 2, a broken top plan view of a strip of metal being processed for the forming of lancets; FIG. 3, a top plan view of an individual lancet; FIG. 4, a sectional detail view, the section being taken as indicated at line 44 of FIG. 3; FIG. 5, a sectional detail view, the section being taken at line 5-5 of FIG. 3; FIG. 6, a sectional detail view, the section being taken as indicated at line 66 of FIG. 3; and FIG. 7, a side view in elevation of the lancet.

The lancet or lancets embodying our invention may be formed from a single sheet 10 of metal such as, for example, non-ductile metal, cold rolled stainless steel, etc., and the individual lancets indicated by the numeral 11 may be formed from the sheet 10 by die cutting or stamping and by grinding operations, as illustrated, by way of example, in FIG. 2. As shown in FIG. 2, the body of the lancet 11 may be formed at an inclination with respect to the edges of the metal strip 10 and with the point 12 of the lancet having a common edge with the edge of the strip 11. The lancets 11 may be sharpened at any atent time or in any sequence. If desired, prior to the separation of the individual lancets 11 from the strip 10, the edge 13 may be sharpened so that each lancet has a sharpened portion 13 forming a section of the sharpened edge of the sheet 10.' It will be understood, however, that the method of manufacture and procedure may be varied as desired. In the grinding operation, for example, the entire edge of the sheet may be ground, as illustrated in FIG. 2, or, if desired, the edge portions between the segment 11 may be first eliminated and only the sections carried by the point 12 sharpened.

In either of the above operations, the edges 13 of the lancets 11 are sharpened while being still held by the sheet 10, so that by this means an effective grinding of the edges of a large number of lancets can be accomplished effectively in one operation. The individual lancet bodies 11 may be separately removed from the metal strip 10 and stamped to provide flutes therein, as will be described more effectively hereinafter, or such operation may be accomplished while the lancets are still held by the sheet 10 and prior to the completing of the die-cutting and removal thereof. As above stated, the sequence of steps may be varied, and any suitable mode of manufacture employed.

The finished lancet is provided with a plurality of flutes or ribs, as can be seen best from FIGS. l, 3 and 6. A large flute 1 4 extends from the rear flared portion of the lancet body forwardly and into the point 12 of the lancet so as to reinforce the point up to the very tip thereof. It will be noted that the rib 14 extends at an inclination to the main body and at an inclination to the cutting edge 13 of the lancet. A second rib or flute 15 extends from the rear of the lancet body and inwardly and forwardly in an inclined direction toward the rib 14. The flutes or ribs 14 and 15 are relatively wide at the rear flared end 16 of the lancet, and narrow as they approach the forward end of the lancet.

The point 12 of the lancet has on one side the inclined sharpened edge 13 and on the other side an unsharpened, rearwardly-extending edge 17 terminating in a curved corner portion '18. The resulting point is substantially in the shape of a right triangle, with the sharpened edge forming one side of the triangle and the unsharpened edge portions 17 and 18 the other sides thereof. The curved neck portion 18 provides, with the adjacent portion 19 of the lancet, a stop or depth-limiting shoulder.

In operation, the lancet point, with the inclined rib and sharpened edge, provides directional cutting both on the surface and below the surface, causing not only immediate penetration, but also lateral cutting so that with a minimum surface lineal cut, there is a maximal number of blood vessels severed by the cutting edge below the surface. The inclined rib 14 not only reinforces the cutting point during penetration, but also provides a resistance, causing lateral cutting and further the additional function of simultaneously opening the wound to promote free bleeding. Thus, while the free bleeding is promoted at the time of collecting the blood for test by the angular position of the flute or rib extending along the point, as illustrated best in FIGS. 4 and 5, quick healing also results because of the small area of surface cutting in a lateral direction.

As shown in FIGS. 3, -4 and 5, the point has an entrance in a single plane, and this progresses into a threedimensional wound so that the compound curvature produces a gaping outlet from the cut area for quick or free bleeding, while at the same time the small area traversed by the cutting edge 13 enables the wound to quickly heal. Further, in the foregoing action, the curved neck portion 18 provides a gradual stop or limit to the depth of pentration. With this structure, there are no Patented Oct. 30, 1962' sharpened or exposed corners to break during the piercing operation.

The wide or flared handle portion of the lan-cet provides a wide gripping surface and allows the blade to be grasped by the fingers and held firmly while at the same time the flutes, as they taper forwardly, reinforce the forward thrusting portion of the lancet, with the result that the small end of the lancet is substantially concealed during the blood-letting operation.

While, in the foregoing specification, we have set forth a specific structure in considerable detail for the purpose of illustrating the inventions, it will be understood that such details of structure or procedure may be varied widely by those skilled in the art without departing irom the spirt of our invention.

We claim:

1. A lancet of thin material having at its forward end a piercing point and a cutting edge on one side of said point inclined laterally and rearwardly, said lancet having an inclined flute extending to said point and forming 20 an acute angle with said cutting edge on one side of said point and a depth-limiting stop on the other.

2. The structure of claim 1 in which the stop portion of said flute is in the shape of a concave bend.

3. The structure of claim 1 in which said Lancet has a 25 flared handle portion and is provided with a plurality of flutes.

4. A lancet of thin rigid material having a pair of flutes extending longitudinally thereof, one of said flutes terminating in a piercing point at the forward edge of said lancet and providing on one side a noncutting stop edge, said lancet having on the side opposite said noncutting edge an outwardly and rearwardly-inclined cutting edge merging with said point, and the other of said flutes being spaced apart from said first-mentioned flute at the rear of said lancet and being inclined toward said firstmentioned flute adjacent said noncutting edge.

5. The structure of claim 4 in which the second-mentioned flute forms a laterally and vertically-extending stop adjacent said noncutting edge of the first-mentioned flute.

6. The structure of claim 4 in which the noncutting edge portion of said first-mentioned flute forms a curved neck joining the noncutting forward edge of said second mentioned flute.

7. A lancet formed of cold rolled stainless steel metal having a relatively wide handle portion and a piercing point at its forward end and provided on one side of the point with alaterally and rearwardly-inclined cutting edge, said handle portion being reinforced with two flutes which are spaced apart near the rear thereof to provide a finger space between the flutes, said flutes converging toward the front of said lancet, with at least one flute forming a portion of the piercing point and also a noncutting, depth-limiting stop.

References Cited in the file of this patent UNITED STATES PATENTS 864,812 Thuillier Sept. 3, 1907 1,021,520 Handloser et a1. Mar. 26, 1912 1,050,121 Frommer et al Jan. 14, 1923 2,706,482 Griffitts Apr. 19, 1955 2,801,633 Ehrlich Aug. 6, 1957 

